Electrically controllable optical filter element

• US 5,510,609 A
• Filed: 09/06/1994
• Issued: 04/23/1996
• Est. Priority Date: 09/13/1993
• Status: Expired due to Term

• Current Assignee: Optrel AG
• Original Assignee: Optrel AG
• Inventors: Ackermann, Emil
• Primary Examiner(s): Westin, Edward P.
• Assistant Examiner(s): LE, QUE TAN
• Application Number:
  US08/301,357
• Time in Patent Office: 595 Days
• Field of Search: 250/201.1, 250/205, 250/204, 250/203.2, 250/203.4, 250/206, 250/214 AL, 359/602, 359/603, 359/604, 359/608, 359/230, 359/267, 359/275, 359/229, 345/87
• US Class Current: 250/201.1
• CPC Class Codes: A42B 3/22 Visors
• CPC Class Codes: A61F 9/023 with variable transmission, e.g. photochromic for welding A61F9/067
• CPC Class Codes: G02C 7/101 having an electro-optical light valve electro-optical elements per se G02F
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

The anti-dazzle assembly comprises an optical filter element whose optical transmission is electrically controllable and an electronic control unit including a light sensitive sensor operatively connected to the optical filter element. The electronic control unit is adapted to vary the optical transmission of the optical filter element in response to the amount of light falling on the light sensitive sensor. This anti-dazzle assembly is controlled such that the intensity of light falling on the exposed surface of the sensor is selectively measured at a plurality of different area portions of this surface. The highest value is selected and used to influence the degree of optical transmission of the filter element. In this way, the anti-dazzle assembly can be controlled much more efficiently insofar as the dangerous high intensity point-shaped light sources are clearly recognized, but strong ambient light does not have a negative influence on the control of the filter element.

Claims

1. A method for controlling an anti-dazzle assembly comprising an optical filter element whose optical transmission is electrically controllable, and an electronic control means including a light sensitive sensor means operatively connected to said optical filter element, said electronic control means being adapted to vary the optical transmission of said filter element in response to the amount of light falling on said light sensitive sensor means, the method comprising the steps of:

projecting the light sources in the area covered by said light sensitive sensor means on the exposed surface of said light sensitive sensor means;

selectively measuring the intensity of said projected light sources and producing output signals indicative of the intensity of said projected light sources by means of a plurality of surface area elements of said exposed surface of said light sensitive sensor means;

selecting the output signal of a surface area element, said selected surface area element producing an output signal indicating that the portion of said projected light sources exposed to said selected surface area element is more intense than the portions of said projected light sources exposed to the other of said plurality of surface area elements; and

using exclusively said output signal of said selected surface area element for the control of the optical transmission of said optical filter element.

2. An anti-dazzle assembly comprising:

an optical filter element whose optical transmission is electrically controllable;

an electronic control means including a light sensitive sensor means operatively connected to said optical filter element, said electronic control means being adapted to vary the optical transmission of said optical filter element in response to the amount of light falling on said light sensitive sensor means;

means for projecting on to the exposed surface of said light sensitive sensor means sources of light present in the room area covered by said light sensitive sensor means;

said light sensitive sensor means comprising a plurality of optoelectric transducer elements in a grid or screen like arrangement, each of said plurality of transducer elements being capable of producing an output signal indicative of the measure of the intensity of the projected light sources exposed to each of said plurality of transducer elements, the output signal of each of said optoelectric transducer elements being individually accessible; and

said electronic control means comprising an electronic circuit means for detecting and selecting an output signal, said selected output signal being produced by said transducer element measuring the highest intensity of the projected light sources exposed to said plurality of transducer elements, said electrical control means using said selected output signal being for controlling said optical transmission of said optical filter element.

3. An anti-dazzle assembly according to claim 2 in which said optoelectric transducer elements are photo diodes.

4. An anti-dazzle assembly according to claim 2 further comprising a semiconductor wafer, said optoelectric transducer elements being located on said semiconductor wafer.

5. An anti-dazzle assembly according to claim 2 in which at least a portion of said electronic control means forms, together with said sensor means, a single constructive unit.

6. An anti-dazzle assembly according to claim 4 in which said electronic circuit means for detecting and selecting said selected output signal comprises a plurality of circuit portions each assigned to one of said electric transducer elements, said circuit portions being located, together with said optoelectric transducer elements, on said semiconductor wafer.

7. An anti-dazzle assembly according to claim 2 in which said means for projecting the sources of light present in the room area covered by said light sensitive sensor means on the exposed surface of said light sensitive sensor means is a lens means located in front of said light sensitive sensor means.

8. An anti-dazzle assembly according to claim 2 in which said light sensitive sensor means is provided with a filter for filtering optical radiation, said filter being located in front of said light sensitive sensor means.

9. An anti-dazzle assembly according to claim 2, further comprising solar cell means serving as a power supply for said optical filter element and said control means.